Several top U.S. health officials have called for the development of new antibiotics to decrease that number.

Silence that could save lives

But USF’s Megan Bolitho believes a sort of ‘silent treatment’ could be more effective at saving lives.

Bolitho’s working to cut off communication between bacteria to keep them from spreading drug-resistant disease.

“Preventing certain species of bacteria from communicating could render them avirulent and incapable of establishing or enhancing an infection,” says Bolitho, assistant professor of chemistry.

Most bacteria are present in humans in small numbers. They lie in wait, quietly multiplying. It’s not until there is a large number, or quorum, that they’re able to mount a coordinated attack — rapidly spreading to overwhelm the immune system. By “shushing” the bacteria, Bolitho and her team of researchers believe they can prevent the bacteria from ever knowing their strength; they won’t recognize whether they’ve reached a quorum or be able to coordinate an attack. Bolitho proved the concept in earlier research with cholera that garnered national attention.

“It’s like a dead space in your cell phone network. The bacteria send out signals, but nothing comes back,” says Emily Murzinski ’14, who received one of four $3,500 student grants to work in Bolitho’s lab. Murzinski never imagined that, as an undergraduate, she’d be part of a team that’s had research published in scientific journals including Nature.

2 million patients infected

Bolitho’s research could pave the way to dramatically reducing the number of deaths in American hospitals, where an estimated 2 million patients contract bacterial infections that contribute to about 90,000 deaths annually. An estimated 70 percent of those infections are resistant to at least one antibiotic, according to the U.S. Centers for Disease Control and Prevention (CDC).

For over a decade, officials at the CDC and the Infectious Diseases Society of America have called for more federal research funding and even legislation requiring pharmaceutical companies to develop new antibiotics. But the science and history shows that bacteria simply finds ways around new antibiotics. “They’ve been evolving for billions of years,” Bolitho says. “They’ve found ways around many of today’s antibiotics, and there’s no reason to think they can’t find their way around more.”

Time to find additional treatments

Bolitho isn’t opposed to new antibiotics in the short term, but blocking bacteria’s quorum sensing communications has two clear advantages. First, pharmaceuticals that impede quorum-sensing communications should only affect bacteria because only they use quorum sensing. That should limit the side effects associated with treatment. Second, inhibiting bacteria’s communication doesn’t pressure them to find a way around the treatment in the same life-or-death way antibiotic drugs do, Bolitho says.

“It could give us more time, maybe much more time, to find additional treatments,” Bolitho says. “Nothing is a panacea. We used to call antibiotics ‘miracle drugs’ because we thought they cured everything,” she says. “Bolitho says. We know better now.”